As a fat bike tire, Surly's Knard adapts the same premise that keeps snow shoes at or near the top of powder, but for a cycling application. Surly crowds a large host of small knobs onto the Knard to increase grip in all terrain conditions and provide lower rolling resistance on hardpack and debris free trails. The Knard's traction is also boosted by its huge girth, as are its float and cushiness. Their blend of size and tread pattern recommend them as the best all around fat bike tire Surly makes. The bombproof 120 TPI and Kevlar bead also mean that you'll be rolling fat with virtually no flats. The Surly Knard Fat Bike Tire comes in size 26 x 3. 8 and fits rims 50 100 millimeters.